Traditional induction watt-hour meters have been produced and used in my country for half a century, and they have played an important role in the measurement and management of energy in the store. But at the same time, it also has some unavoidable problems. Therefore, subsequent electric energy meters have been continuously improved. For example, electronic energy meter have made great improvements in the calculation accuracy and the wear of structural components.
Due to cost, modern electronic instruments, including electric energy meters, do not tend to use high-precision components such as sampling resistors but use high-stability but low-precision components, which are corrected digitally. The relationship between the U and I results obtained by ADC sampling and the value of the sampling component is a one-time function, so it only needs to be calibrated back after a one-time correction. Some metering chips have internal calibration registers, and there is no problem. It is necessary to operate the metering chip. MCU, MCU has a lot of space for calibration parameters, which means that as long as the calibration parameters are changed, the output power result can be changed.
This method is also applicable to single phase meter , so the counting is basically not wrong.
